Experimental investigations of nanofluids convective heat transfer in different flow regimes: A review

Abstract

Many claims of strange/unpredictable change of convective heat transfer in different flow regimes, especially laminar flow regime have been included in nanofluid literature. In this present work, convection of different nanofluids mostly including Al2O3, TiO2 and CuO in various base fluids such as water has been carried out experimentally. The influence of various parameters including volume concentration, Reynolds, Nusselt, Rayleigh and Peclet Numbers, thermophoresis, decreasing thickness of thermal boundary layer, nanoparticles thermal dispersion and nanoparticles migration on heat transfer rate or heat transfer coefficient are considered. Moreover, heat transfer experiments show the heat transfer coefficients of nanofluids are higher than the base fluid. There are some significant factors such as quantity of the aforementioned numbers and the geometries inclinations that have been explained in details in this study. Likewise, the results depict that rate of heat transfer or heat transfer coefficient is enhanced with augmentation of some parameters including volume concentration, Nusselt and Reynolds numbers. However, according to the results, the classical Shah model is failed to forecast the convective heat transfer behavior of nanofluids in laminar flow.